Privacy Policy
Last updated: March 6, 2026
The short version: Lumero is designed so that we never have access to your messages, calls, or files. We collect as little data as possible to operate the service. We don't sell your data, we don't show you ads, and we don't build profiles about you.
1. Who We Are
Lumero is operated by Nemean Software, LLC ("we," "us," "our"). This Privacy Policy explains how we collect, use, and protect information when you use the Lumero mobile application and related services (the "Service").
2. Information We Collect
2.1 Account Information
When you register for Lumero, we collect:
- Phone number — Used to create your account and allow others to find you. Your phone number is stored in hashed form on our servers.
- Profile information — Your display name and profile photo, if you choose to set one. This information is end-to-end encrypted and not accessible to us.
2.2 Technical Information
To deliver messages and maintain the Service, we process:
- Push notification tokens — Required to deliver notifications to your device. These are device identifiers provided by Apple (APNs) or Google (FCM).
- Public encryption keys — Your public key material is stored on our servers to enable end-to-end encrypted key exchange with other users. We never have access to your private keys.
- Delivery metadata — Timestamps of when messages are received by our servers for delivery. We do not store message content.
2.3 Analytics
We use PostHog to collect anonymous usage analytics that help us improve the app. This includes:
- App launch and session events
- Feature usage patterns (e.g., which screens are visited)
- Crash and error diagnostics
Analytics data does not include message content, contact information, or any data that is end-to-end encrypted. PostHog data is sent to servers hosted in the United States. You can learn more about PostHog's data practices at posthog.com/privacy.
2.4 Information We Do NOT Collect
Lumero is designed to minimize data collection. We do not collect or have access to:
- Message content (text, images, videos, files, voice messages)
- Your contacts or address book
- Location data
- Call content or call logs
- Browsing history or app usage analytics
- Device identifiers for advertising purposes
- Biometric data
3. End-to-End Encryption
All messages, media, and files sent through Lumero are protected with end-to-end encryption using the Signal Protocol. This means:
- Messages are encrypted on your device before being sent and can only be decrypted by the intended recipient.
- We cannot read your messages, listen to your calls, or view your files — even if compelled to do so.
- Each message uses a unique encryption key that is deleted after use (forward secrecy).
- Group messages are encrypted individually for each participant.
Exception — User-Initiated Reports: If a user chooses to report a message, a decrypted copy of the reported content may be forwarded to us for review. This is a deliberate action taken by the reporting user on their device — we cannot access message content in any other way. Reported content is used solely to investigate potential violations of our Terms of Service and is deleted after the review is complete.
4. How We Use Your Information
We use the limited information we collect solely to:
- Create and maintain your account
- Deliver messages and notifications to your device
- Enable other Lumero users to find you (if they have your phone number)
- Facilitate end-to-end encrypted key exchange
- Prevent abuse and enforce our Terms of Service
We do not use your information for advertising, profiling, or any purpose unrelated to providing the Service.
5. How We Share Your Information
We do not sell, rent, or trade your personal information. We may share limited information only in the following circumstances:
- Service providers — We use Apple Push Notification service (APNs) and Google Firebase Cloud Messaging (FCM) to deliver push notifications. These services receive push tokens but not message content.
- Legal requirements — If required by law, we may disclose the limited account information we have (phone number hash, account creation date, last connection date). Because messages are end-to-end encrypted, we cannot provide message content in response to any legal request.
6. Data Retention
We retain your information only as long as necessary:
| Data Type | Retention Period |
|---|---|
| Account information | Until you delete your account |
| Public encryption keys | Rotated regularly; old keys are deleted |
| Undelivered messages | Stored encrypted on our servers until delivered, then deleted (max 30 days) |
| Push tokens | Until you uninstall the app or revoke permissions |
7. Data Security
We implement appropriate technical and organizational measures to protect your information, including:
- End-to-end encryption for all message content using the Signal Protocol
- TLS encryption for all network communications
- Hashed storage of phone numbers
- Regular security reviews of our infrastructure
8. Your Rights and Choices
You have the following rights regarding your data:
- Access — You can request a copy of the data we hold about you.
- Deletion — You can delete your account at any time from the app settings, which removes your data from our servers.
- Disappearing messages — You can set messages to automatically delete after a chosen time period.
- Notifications — You can disable push notifications through your device settings.
- Block contacts — You can block any user from contacting you.
9. Children's Privacy
Lumero is not intended for use by children under the age of 13 (or the applicable minimum age in your jurisdiction). We do not knowingly collect information from children. If you believe a child has provided us with personal information, please contact us and we will take steps to delete it.
10. Camera, Microphone, and Media Permissions
Lumero requests access to your device camera, microphone, and photo library solely to allow you to:
- Take and send photos or videos in conversations
- Record and send voice messages
- Set a profile photo
- Send existing photos and videos from your library
Photos, videos, and voice messages you send are end-to-end encrypted. We do not access your camera, microphone, or photo library for any other purpose. These permissions are requested only when you initiate the relevant action (e.g., tapping the camera or voice message button). You can revoke these permissions at any time in your device settings.
11. International Data Transfers
Your encrypted messages are routed through our servers, which may be located in different jurisdictions. Because all message content is end-to-end encrypted, the content of your communications is protected regardless of server location.
12. Third-Party Services
Lumero integrates with the following third-party services:
- Apple Push Notification service (APNs) — For delivering notifications on iOS. Subject to Apple's Privacy Policy.
- Google Firebase Cloud Messaging (FCM) — For delivering notifications on Android. Subject to Google's Privacy Policy.
- PostHog — For anonymous product analytics to help us improve the app. Does not receive message content or encrypted data. Subject to PostHog's Privacy Policy.
- Amazon Web Services (AWS) — Our server infrastructure is hosted on AWS. Encrypted messages pass through AWS servers but cannot be read by AWS or us due to end-to-end encryption. Subject to AWS's Privacy Policy.
We do not integrate any advertising SDKs or social media SDKs.
13. Changes to This Policy
We may update this Privacy Policy from time to time. We will notify you of any material changes through the app or by other appropriate means. Your continued use of Lumero after changes take effect constitutes acceptance of the updated policy.
14. Contact Us
If you have any questions about this Privacy Policy or our data practices, please contact us at: